Peripersonal Space from a multisensory perspective: the distinct effect of the visual and tactile components of Visuo-Tactile stimuli

Abstract

Peripersonal Space (PPS) is defined as the space close to the body where all interactions between the individual and the environment take place. Behavioural experiments on PPS exploit multisensory integration, using Multisensory Visuo-Tactile stimuli (MVT), whose visual and tactile components target the same body part (i.e. the face, the hand, the foot). However, the effects of visual and tactile stimuli targeting different body parts on PPS representation are unknown, and the relationship with the RTs for Tactile-Only stimuli is unclear. In this study, we addressed two research questions: (1) if the MVT-RTs are independent of Tactile-Only-RTs and if the latter is influenced by time-dependency effects, and (2) if PPS estimations derived from MVT-RTs depend on the location of the Visual or Tactile component of MVTs. We studied 40 right-handed participants, manipulating the body location (right hand, cheek or foot) and the distance of administration. Visual and Tactile components targeted different or the same body parts and were delivered respectively at five distances. RTs to Tactile-Only trials showed a non-monotonic trend, depending on the delay of stimulus administration. Moreover, RTs to Multisensory Visuo-Tactile trials were found to be dependent on the Distance and location of the Visual component of the stimulus. In conclusion, our results show that Tactile-Only RTs should be removed from Visuo-Tactile RTs and that the Visual and Tactile components of Visuo-Tactile stimuli do not necessarily have to target the same body part. These results have a relevant impact on the study of PPS representations, providing new important methodological information.

Pain and the Perception of Space in Fibromyalgia: Effects of Pain in Estimations of Distance

“…Without this simulation, the task is carried out by means of visual strategies, with errors in estimations that are not in uenced by distances and ramp inclination. These results provide evidence of the role of the current internal states of the body in space representation in the presence of chronic pain, thus supporting previous studies on healthy and deafferented groups (Beccherle et al, 2022;Scandola et al, 2020;Moro et al, 2023).…”

The relationship between action, social and multisensory spaces

“…These findings contrast with the single-cell recording studies in monkeys showing that the receptive fields of the multisensory neurons are within RS 2 . However, one may hypothesise that the sensory facilitation reported in the behavioural studies and the neural mechanisms highlighted in the single-cell studies do not refer to the exact same multisensory integration process 90 . While the link between the two has been strongly advocated 30 , it is apparent that the behavioural multisensory facilitation effect in humans is more flexible than what was reported in single-cell studies.…”

“…As evidence, multisensory facilitation in behavioural studies has been found to be altered by the valence or meaning of the visual/auditory stimulus 69 , individual traits such as anxiety/phobia 46 , interoceptive traits 41 , bodily changes such as pregnancy 42 or limb immobilisation 91 , and even lockdown experience 88 . Moreover, a number of studies indicated that the visual/auditory stimulus does not have to target the same body part as the tactile stimulation to trigger multisensory facilitation 90 . This might be because the behavioural effects evidenced arose not only from the multisensory brain areas but also from their interaction with other brain areas such as those involved in body representation 92 and object-directed action control 7 .…”